An electric toothbrush with a drive mechanism comprising gearwheels is known for example from DE 39 37 854 A1. The drive mechanism converts a continuous rotary movement of the drive shaft of an electric motor into a reciprocating pivoting of a driven shaft. EP 0 850 027 B1 and EP 1 357 854 B1 disclose further drive mechanisms with gearwheels wherein the mechanisms further generate an additional pivoting of the drive shaft about a swiveling axis. The use of gearwheels may contribute to increased sound emissions.
U.S. 2006/0101598 A1 discloses an electric toothbrush with a scotch yoke mechanism converting a continuous rotary movement of the drive shaft of an electric motor into a reciprocating longitudinal displacement of a driven shaft.
Further, U.S. Pat. No. 5,381,576 describes an electric toothbrush comprising a housing, an electric motor with a drive shaft having a first rotary axis and a drive pin connected to the drive shaft eccentrically with respect to the rotary axis, and a driven shaft having a second rotary axis and mounted in the housing for performing a pivoting about the second rotary axis. The driven shaft is indirectly coupled to the drive pin by a gear mechanism converting a rotary motion of the drive shaft into a reciprocating pivoting of the driven shaft. The gear mechanism comprises an elastically deformable transmission member.
U.S. Pat. No. 5,689,850 and EP 0 110 327 A2 disclose electrically driven toothbrushes comprising a scotch yoke mechanism for converting a rotary motion of a drive shaft into a reciprocating pivoting motion of a driven shaft. In U.S. Pat. No. 5,689,850 the driven shaft pivots about an axis perpendicular to the axis of the driven shaft, whereas in EP 0 110 327 A2 the driven shaft pivots about its longitudinal axis.
It is an object of the present disclosure to provide an electrically driven device with reduced sound emissions.